Cataclysmic.bat and/or Cataclysmic.exe can be executed from a USB, it's customizable and very simple to understand. (In the script i have comments after every command explaining what's going on)
Estimated Time Running Cataclysmic: About 8 seconds, then you can just unplug the USB.
What It Does:
It forces the computer to shut down everytime it starts up. A simple way around this is to start up in SafeMode, but SafeBoot will be deleted when running the file so the target will be unable to boot up in safemode. The shutdown file will be added to the Startup folder but also the Registry. So if the file is deleted in Startup folder, it will still be in Registry (and the other way around)
What If I Accidentally Run It?
When downloading you will be downloading 2 files.
Cataclysmic.bat
PhantomFix.bat
If you run PhantomFix.bat it will delete the shutdown file in Startup and Registry, so that you safely can turn your computer on/off. BUT, it will not get SafeBoot back (SafeBoot is not necessary unless you have to start it in SafeMode)